Clutch control mechanism



March 18, 1952 R. H. WHEELER CLUTCH CONTROL MECHANISM 2 SHEETSSHEET 1 Filed June 10, 1947 .m E EH E W m UH A m H CY /B E "Q CHHHU' March 18, 1952 R. H. WHEELER 2,589,649

CLUTCH CONTROL MECHANISM Filed June 10, 1947 2 SHEET$SHEET 2 E9. 4 INVENTOR.

QQHAED ft WHEELER A 7'TOENE Patented Mar. 18, 1952 U NITED STATES PAT ENT OFF 1 CE 2,589,649 CLUTCH ,con'rnon MECHANISM Richard "H. Wheeler, Utica; Mich, assignon to Bendix-Aviation Corporation, SouthBend,vInd., a corporation of Delaware ApplicationJ nne-lil, 1947, Serial No. 753,682

invention relates in general ,to power means for operating'the friction clutch of an automotive vehicle .and in particular to clutch op ting pr ssu e di en a p a edp w l means controlled by the operation of an accelerator'controlled pressure balanced valve.

Another object of my invention is'tO Drovide, in the power plant of an automotiv vehicleincluding a; friction clutch and anjaccelerator; 1a yacuum operated clutch control mechanism comprising 'acvsin'gle actineifluid ressure moto ai m?" be n controlled :by a flueeeway telwful valv which tuated. t ough. the: in ermedia y 1 a floatin l ver, 'b 'th a ce erato and art-$ differential and, spring operated motor.

1 Yet another object of my invention istoprovide power means for operating; the" friction clutch of an automotive vehicle saidpower means serving to effect two stages of clutch engaging I movementjpf the driving element of the clutch i mwesjinto enga ment wit the, driven .element of the clutch said two stage operation. of the clutchdriving element being effected by a throttle opening movement of the accelerator.

short time reguired to bring the gaseous pressure within the motor back to atmosphericcp fess'ure. Yet another object of my invention is to provide mechanism for operating one of the clutch plates of a friction clutch to efiect a disengagement of the clutch and for controlling the movement of said plate to effect an engagement of the clutch, said mechanism including a vacuum oper- 4 Claims. (01.- 192-075) Figure 1 is a diagrammatic view disclosing a "clutch controlgmechanism including the valve means constituting the essence of my invention.

' and Figure '3 is ;a sectional view disclosing a modification of the mechanism of Figure 2.

ated motor, afollow up valve for controlli g the" operation of said motor,-saidvalve being adaptedto be movedto a lapped position to cut-off the flow; of air from the motor; and means, including adjustable stop means and a 'spring-and-pressure Figure 4 is a view disclosing the principal parts of the connection interconnecting the accelerator,

lng's the principal elements thereof consistetra single acting vacuum motor 10 comprising a casing l2 and a power element such as a piston "I.

which-is connected to a friction clutch of a-cori- '-ventiona1 design, including a driving plate IS, a -driven plate l5 and a clutch spring 11.

One-end of-the casing of the motor, a portion of the body thereof and the power element together outline a control chamber 5, the gaseous pressure within said chamber being controlled to control the operation of the motor. The force transmitting means interconnecting the power element of the motor with the clutch preferably includes a flexible cable l4 connected to a crank 16; and said crank is fixedly connected to a shaft it! which is connected to the clutch. A foot operated-clutch pedal 20, conta-ctable with a flange 2| extending from the crank I6, is also preferably included in the clutch operating mechanism.

One end of the motor I O, that is the end of the same constituting apart of the aforementioned power compartment 5 of the motor, is connected by a conduit 22 to a compartment 24 of a control valve unit indicated as a whole by the reference numeral 25 disclosed in Figure 2. The cas- "ing 26' of the unit 26 is provided with a cylin- 4o dri-cally shaped bore to receive a cylindrical sleeve valve member 28 constituting one of the two parts of a three-way valve; and said casingxis difierential operated motor, 'for operating the valve-to automatically efiect alapping thereof to limit the clutch disengaging evacuation of the motor to acertain factor; and forlapping said alve-to control-the clutch engaging operation of the motor.

Other objectsof the invention will appear more -fully hereinatter from the "followingdetailed description when taken in connection with'the 1 Iii-beyond the valve-member 30 and is detachably accompanying drawings, wherein a single emcounterbored to provide the aforementioned compartment 24, Figure 2.

-A valve member 30, which is biased inwardly ric'al'ly spaced-openings to receive therethrough a. pin 32 andsaid pin extends through a connecting pin 34. one end of which extends within the .member 30.The other end of the pin 34 extends connected to a tvro-partlever 3G. The end portion 38 of the pin 34 is preferably biased into engagement with the interior of the valve 30 by a coil spring 40. There is thus provided means for readily disconnecting valve 30 from the lever 36; for the pin 32 may be removed by driving the same through'the pin-34, thereby separating the latter from the valve :0.

As is disclosed in Figure 2, the lever 36 is pivotally connected at one of its ends to a rod 4|; and the movement of the rod to the left, Figure 2, is limited by a stop pin 42 adjustably mounted in the valve casing. The .othere nd oi the lever 36 is pivotally connected tol a pin 43 which; is slidably received at one of its ends in a'por-uz tion of the valve casing and which is secured at its other end to a flexible diaphragm" 441" This diaphragm constitutes the power "element;-

of a valve operating pgjessure differential operated motor indicated as a whole by. the reference numeral 45; and the operation ofsaid motor is in large measure controlled by the gaseous pressure within'a control compartment 46 of said motor, and by compression springs v4'I-an,d 51 A compartment 48 which is adapted, in the operation of-the valve,

to be positioned to register the recess I with ports 53 in the valve member ;28. The. member 30 is also operated so thatthe land portion 52 covers the ports 53, that is, laps the valve and is also operated to interconnect said ports with-,

the air cleaner 50 via the motor compartment 48 and theinterior of thevalve.

The valve member 28 is provided,- with an opening 53 to register with one end of a duct 54 in the valve casing, said-duct registering atits other end with a chamber 55 to which is connected a conduit 63 leading to the intake manifold (SI of the internal combustion-engine 62 of the car.

Completing the description of the valve unit. .26 the casing 26 is provided with a duct-92,. Figure 2, permanently interconnecting thecontrol compartment 45 of the motor 45, with the'aforementioned valve compartment 24. There is thus provided fluid transmitting means :for -at 811;;

times interconnecting the motor compartment 46, the valve compartment 24, and'thecontrol compartment 5 of the clutch operating motor [.0. It follows therefore that the operation of the clutch control, mechanism constitutingmy in-s,

vention is controlled by controlling the gaseous pressure within the valve compartment 24.

There is thus provided a compact valve control unit 26 comprising a multl-sectional' casing housing a three-way control valveand also hous-..,;.

ing means for operating said valve comprising a spring and pressure differential operated motor and an accelerator operated pm, said pin and the power element-of the motor being connected with the movable part of said valve-by means of a floating lever-member. f-

Describing now the force transmitting means interconnecting the accelerator II8 of the; car

with a throttle operating crank 'I20- and with the valve operatingpinfl; said pin is cojnnected'g-i to-a rod 88 and thisrodyis'pivotallyyconneetcd end of this lever member is pivotally mounted upon a floating pin I22 and one end of this pin is mounted in one end of a bell crank lever I24 which is pivotally mounted upon a fixed pin I26. The lever member 90 is connected to the accelerator-311.8 byimeans oi arod- I28, a bell crank ,lever I30 and a link I32 .all as disclosed in Figure 1; and as disclosed in the latter figure, the

-bell crank lever I24 is connected to the throttle l q valve ot the carburetor by means of a link I34, a 'crank I36; a rod I38, a crank I40, a link I42 and the crank I28.

. A spring I44, which is .-weakerthai1; athrottle return spring I45, is 0perative,- -tOge1 hI.:With the spring I45, to return the accelerator to its throttle closed position and to move'thevalve member 30 to the right, Figure g to open the three-way valve, that is operate the same to effect a clutch disengaging operation of the motor ID. The spring I44 is preferablyfslee'ved over the pin I22 and is connected at it's ends to the levers 90'and I24. Theiopera- 1' tifon'bf this part of the mechanism of my inventi0n; w i1l' be described hereinafter when the pperation of the entire clutch control mechanism is describedin'detail.

Describing now the complete operation of the mechanism" constituting my invention and incidentally'coinpletingthe description of the parts .not heretofore described; when the accelerator f l'|8 iS"i' e'Iea'Sed to close; the. throttle and idle the internal combustion engine 114, the intake manifoldfl I2 of saidQenei e is partially evacuated. There is" thusf'pr'ovided'a source of vacuum for energizing. themotor I 0 to disengage the frictionclutch of the motbr'vehicle; and this operationis effected inasmuch as with the release of the accelerator the movable three-way. valve. member 30 moved'to place said motor in air transmittingjconnection with the manifold. In

this operation of disengaging the clutch, the valve member '30 and the means for operating the same "assume the relative positions disclosed in Figure 2, it being noted that the valve is lapped.

Describing this .,clutch disengaging operation of the valve 30, when the accelerator is released. the accelerator return spring I moves "the end of'the lever '36 to'the position shown in Figure 2 a stop member on the rod 4I serving to limit said movement. The valve operatingmotor 45 is' at this time de-energized accordingly .the springs .4lr'and 51 are expanded,,that is, in -tl eir. .free length state; Now the parts of the mechanism are so constructed and arranged that .theyalve 3.0 then in a position to intercon- 6 nect the. ports-53 and 53'... Accordingly, 'the above described clutch disengaging operation is .eflfected, that is,.the compartments of the motor .IB is..placed in air transmitting connection with the intake manifold to evacuate said motorgthereby energizing L'the same to disengage the clutch. In this operation-air is withdrawn from the motor I0 and the valve operating cornpartment 4B,; intothe intake manifold via the conduit 83,.the valve compartment 55, the conduit'54-fiv-alve recess 5I, ports 53, thecompart- .ment 24,- theconduit 92- interconnecting. the .compartment 2'4 with the-valve motor compartment 46, and -the c ond uit 22-connecting the compartment 24 with the control chamber 5 of the clutch 7o motor. i

As air is withdrawn from-the motor compartment 4-S, the piston44 ismmovedto the-left of Figure; fitto compress the high rate spring 51 and low rate'gspring 41 and thermost importantlfeawith a lever member 90, Figure 4. The lower ture of my invention lies in the provision of the,

aceaeaar member '30 is positioned as disclosed in Figure '2',

that-is, its lapped position. In other words, the valvemechanism 26 is automatically operative, upon release of the accelerator, to efiect a certain factor of evacuation of the motor I0. This degree of evacuation is preferably less than that effected in the conventional clutch operating vacuum motor of the day; and by so minimizing the clutch disengaging vacuum of the motor, the clutchiena gaging operation of-said motor is expedited. Ex-.

plaining the latter feature of my invention,if the motor I0 is subjected to a relatively low vacuum in. effecting the disengagment of .the clutch, it follows: that the engagement of the. clutch will'be: expedited, this by virtue of the relatively short time required to' bring the gaseous pressure withinzthe compartmenti back to atmospheric pressure. ;In other words, .by limiting the clutchidisengaging vacuum of the motor I0 to a relatively 1ow:factor, there is provided means for effecting a relatively fast clutch engaging operation of said motor.-

Continuing now the description of the cycle of clutch control. operations of .the motor Ill, said motor having-been energized to disengage ;the.- clutch the driver'will then probably wish-to es-. tablish the change speed transmission of the ve-- hicle in a relatively low gear setting. Thisis, of course, -done by moving the transmission controlling-selector lever, not shown, to: its low gear," position.

Continuing now the description ofthe cycle of operations of the clutch control mechanism the power plant of the vehicle is now prepared-to effect a forward movement of the vehicle accordingly. the .driver depresses the accelerator to open the throttle and effect a clutch engaging operation of the clutch operating power meansl Describing the latter operation with the firstincrementiof movement of the accelerator the lever 90 is r0:-

tated. counterclockwise about thewpin I22 as a fulcrum, this operation being-made possible..-by virtueof the fact thatthespring. I44 is weaker" than the throttle spring..l45 and thelatter-spring is strong enough to prevent therotation. of the lever I24; In this operation the lever Bil-moves counterclockwise until a flange 204 at the upper end of the same contacts an adjustable stop; 206 onthe lever I24; and this movement of the lever; floresultslin a movement of the rod 88 to the left; Figure 2; torotate the lever member- 35 about; itsr. pivotal connection with the pin 43 as a fulcrum. The valve member is thus moved-to the lefii Figure'2ythe lever operating as'a lever-of-the second class to place the valve-ports -53 incommunication with a valve chamber 2I0---which chamber is at all times connected-to theatmosphere-via the-interiorof the valve member 30 and; the-valve compartment 48 which. is -at =all vented'to the atmosphere via the air cleaner -.5Il.-

It'is. to benoted that in this initial operation of. the-valve the; degree of movement of the-valvemember 30 is greatenpreferably about twice asgreat, as .the degree of movement of the rod I28.

outin the description-that.follewsthere is thus.

provided a valve operating mechanism operative to. quicklyefiect the first stage operation ofthemotor I llrduring'the first increment of depression of the accelerator, said increment being relatively small.

-. 'I'he valve member 30 having been moved to the left-to vent the valve compartment 24 to atmo s.--. phere there results a relatively rapid flow-of air into both the control compartment 5 of the clutch operating motor I 0 and the compartment 46 of the valve operating motor and this flow-of air results in a clutch engaging operation of the motor,

IOL. Describing this operation the power element I of the motor I0 is moved to the right, Figure l. by the clutch springs." and when said springs have expanded suificiently-to bring the clutch plates into lightv contact. with eachother,.-the movement ofthe power element is arrested.

Explaining thisarresting operation the clutch spring. H, by its .expansion,-fserves to maintain a relatively low gaseous pressure, that is vacuum,.

within;the'joontrolchamberz 5 of the motor 10. Now-inasmuch. as said control chamber-is at all times'connected to the valve chamber 24' and motor-chamber 46 it follows that the gaseous pressure within said chambers is also maintained relatively low by virtue' of the expansion of the,

clutch springs.-- As described above, when the clutch springs have extended a certain amount,

that is, when their. vacuum creating pulling power h'asxdecreased to .a certainfactor, then the com-- pressed springs 41 and 51 expand thereby lapping theethreeeway ;valve-;-28, 30, said position of the a valve being disclosed in Figure 2.- Describing this operation of the valve the valve member 30 moves to-gthe right until-the ports v53 register with the land portion52-of said .valve member; and when this occurs-the. fiow. of air into the chamber 46 and the motor; I O-is automatically cut off and the system is then in equilibrium. v

In this operation the lever rotates counterclockwise about the pivotal connection between the pin I22-and said lever, said pivotal connection acting as a fulcrum. As stated above, the parts of the mechanism of my invention are so constructed and arranged particularly the strength or load of the clutch-springs, the area of the diaphragm 44 and the rate factor of the spring 41, that the valve i lapped to arrest the movement of the power element of the clutch motor when the clutch plates are in light contactwith each other. It is to be particularlynoted that when the valve 28, 30 is lapped to complete the above described first stage clutch engaging operation of the mechanism, that the high rate spring 51 is spent, that is exerts no load on the piston 44.

This operation of the motor I0 is usually described as the firststage operation thereof and it is to be noted. that by varyingthe rate of. the springs 41 and 51 that the termination of the first stage operation of the motor may be .varied. In otherwords,. by varying the rate of the springs 41'- 'and .Elthere is provided means for varying the degree of loading of .the clutch plates or the de-- gree of separation of said plates when the first stage of clutch engaging operation ofthe .motor L0 is completed. It is to be noted the mechanism mv invention .is preferablyso constructed that;

this first stage ofclutch engaging operation of said motor is completed shortly after or at sub-' pleted very quickly and with" a normal operation of the accelerator the driver'may momentarily arrest the depression thereof-when the resistance of the throttle return spring I45 is encountered; and this momentary arresting' of the depression of the accelerator will sufiice to insure a completion of the aforementioned first stage of clutch engaging operation of said motor before the throttle is opened. I

To effect the step by step second stage of clutch engaging operation of the motor 10 the driver continues the depression of-.J the accelerator thereby effecting a clockwise rotation of the bell crank lever I24 to open the throttle; and this operation of the accelerator serves to again effect a leftward movement of the rod 88 and a leftward movement of the valve member 30 the lever 36 again fulcruming about its pivotal connection with the pin 43. This Operation, as with the above described first stage clutch engaging operation 'of the motor, serves to again place theclutch motor compartment 46 and the control compartment of the clutch motor I in communication with the atmosphere, thereby decreasing the gaseous pressure therein. The clutch springs then automatically resumetheir expansion to force the clutch plates into contact with each other. As before, if the driver arrests the movement of the accelerator after this resumption of movement of the valve member 30 said member again moves to its lapped position by virtue of a resumption of'the e'xpansion of the spring 41. In this 'valve lapping operation the direction of movement of the valve member 30 is again reversed, the lever 38 fulcruming about its connection with the pin 4|. with the above described first stage 'of clutch engaging operation of the mechanism the spring 41 expands to move the valve member 30 to its lapped position when the differential of pressure acting on the diaphragm 44 is reduced to a certain factor by the fiow of air into the chamber "48. As with the first stage operation of the mechanism, the valve is lapped when the force exerted by the spring 41 equals the force exerted by the diaphragm 44.

The clutch plates are thus first moved into light engagement with each other and then pressed into a firmer contact, said latter operation being effected by a succession of steps if the driver chooses to depress the accelerator by a succession of steps; and he will probably do this if he desires to effect a slipping operation of the clutch. The latter operation, is, of course, necessary in efiecting a very slow movement of the car such as when parking the same. The first stage operation of the mechanism, that is the operation to effect the relatively rapid movement of the clutch plates into light engagement with each other, will, by virtue of the relatively fast movement of the valve member 30 and its degree of class, the lever 90 and I24 moving as a unit about the pin 126; and by virtuegf this operation the degree of clutch engaging movement of the valve member 30 is relatively small compared tothe. degree of movement of the accelerator to eifect said movement. It is also to be remembered that the first stage of clutch engaging operation of the clutch is, with a r prmal operation of the accelerator, completed very shortly after or at substantially the same time as the opening movement of the throttle is initiated. The adjustablestop 42 serves to control the mechanism to limit the clutch plate loading factor said factor preferably being such as to prevent a stalling of the engine.

The clutch being engaged and the accelerator partially depressed the driver then further depresses the accelerator to steep up the vehicle with the transmission established in low gear; and when the desired vehicle speed is attained the driver will then release the accelerator preparatory to establishing the transmission-imahigher gear ratio setting.

There is disclosed in Figure 3 another embodiment of my invention, the parts disclosed in said figure duplicating like parts disclosed in Figure 2 being given the same reference numeral with the addition of a prime. The valve mechanism of Figure 3 differs from that disclosed in Figure-2 only in the adjustable means for determining the lapping operation of the valve to limit the degree of evacuation of the clutch motor. This adjustable means of Figure 3 lies in the provision of a stop 69 adjustably mounted in th valve casing and serving to determine the accelerator released position of the pin 4|, and a. threeprong leaf spring 56 interposed between one side of the piston 44' and the interior of the valve casing. As with the spring 51 of Figure 2, the leaf spring 56 functions as a yieldable stop cooperating with the remainder of the valve operating mechanism to effect a lapping of the valve when the gaseous pressure in the compartments 5 and 45' reaches a certain factor. With. the mechanism of Figure 3, the accelerator released position of pin 4| is adjusted by the stop 69, there being no adjustment of the leaf spring 56; and with the mechanism of Figure 2, the adjusting operation is effected by the setting of the screw 51', there being no adjustment of the accelerator released position of the pin 4|. With the mechanism of both embodiments of my invention there is provided adjustable means for controlling th lapping operation of the valve, said operation determining the degree of evacuation of the motor 10 when the clutch is disengaged.

There is thus provided, by the friction clutch control mechanism of my invention, power means, including a pressure differential and spring operated motor controlled by a pressure balanced follow up valve for' controlling the operation of the clutch, the time required to engage the clutch being reduced to a minimum.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and though said invention has been illustrated in connection with but two modifications thereof it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment.

I claim:

1. Mechanism for operating the clutch of an engine driven vehicle comprising a fluid pressure motor, a follow-up valve including two relatively movable members, for controlling the operation of said motor, and means for operating said valve including means for determining the degree of movement of one of the valve members in one direction and cooperating with other parts of the mechanism to limit the energization of the motor in its operation of disengaging the clutch, said valve operating means including a floating lever operably connected to one of the parts of the valve, manually operated means connected to one end of the lever, a pressure difl'erential and spring operated motor connected to the other end of the lever, and stop means, including a plurality of sequentially operable springs, positioned in contact with the power element of the latter motor, for determining a certain position of the lever to thereby effect the aforementioned controlled energization of the motor said stop means also serving to control the clutch engaging operation of the motor.

2. Mechanism for operating the clutch of an engine driven vehicle comprising a fluid pressure operated motor, a follow-up valve for controlling the operation of said motor, and means for controlling the operation of said valve to efiect a limited energization of the motor in its operation of disengaging the clutch and to effect a step by step de-energization operation of the motor to efiect a step by step clutch plate loading operation of the clutch, said valve operating means including a floating lever, a pressure diflerential operated motor including a power element operably connected to one end of said lever, and spring means, including a high rate spring and a low rate spring, acting sequentially upon said power element to control the operation of the latter motor the high rate spring serving to control both the clutch disengaging operation of the motor and the first stage of clutch engaging operation thereof.

3. In an automotive vehicle provided with an accelerator, an engine controlling throttle, and a friction clutch comprising a driving plate, a driven plate and yieldable means for forcing said plates into engagement with each other; power means for moving the driving plate out of engagement with the driven plate and for controlling the operation of the yieldable means to effect a stage engagement of the clutch, said power means including a fluid pressure motor, a two part follow-up valve for controlling the operation of said motor, and means for controlling the operation of said valve including a lever, force transmitting means, including a lost motion connection, interconnecting the accelerator, the throttle and one end of said lever, a pressure differential operated motor having its power element operably connected to the other end of said lever, spring means including a high rate spring and a low rate spring acting sequentially upon the power element of the latter motor and operable to control its operation; the parts of said mechanism being so constructed and 'ar' ranged and so operative as to effect the first stage of clutch engaging operation of the driving clutch plate when the accelerator is depressed to take up the lost motion in its connection with the throttle the high rate spring operating, at this time, in eifecting this first stage operation; to efiect the second stage of the clutch engaging operation of said driving clutch plate as the accelerator is depressed to open the throttle, and to effect a limited energization of the clutch operating motor when the accelerator is released, the high rate spring controlling the valve to effect the latter operation.

4. In an automotive vehicle provided with a throttle, an accelerator and a friction clutch comprising a driving element, a, driven element, and yieldable means biasing said driving element into engagement with the driven element; power means for separating the driving element from the driven element against the tension of said yieldable means for controlling by a stage operation, the movement of said driving element into engagement with the driven element, and for synchronizing the opening of the throttle with the latter operation; said power means including a fluid pressure operated motor operably connected to the driving element, afollow-up valve for controlling the operation of said motor, means for controlling the operation of one of the parts of said valve including a floating lever; a fluid pressure operated motor having its power element connected to one end of the lever, force transmitting means interconnecting the other end of the lever with the accelerator, a high rate spring and a low rate spring, adapted to act sequentially upon one side of the power element of the latter motor the former spring cooperating with other parts of the mechanism to effect the first stage of clutch engaging operation of the mechanism, and force transmitting means interconnecting the throttle with the aforementioned force transmitting means.

RICHARD H. WHEELER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

